The present invention relates to a disc brake with automatic adjusting device.
European patent No. 0 403 635 discloses an adjusting device of this type. In the prior art device, a nut screwed to a spindle is integrally formed as a combination unit along with a coupling element having a conical friction surface and an auxiliary piston, slidable in a bore of the brake piston. A device of this type necessitates exact coaxial positioning of the spindle, the combination unit and the bore of the brake piston. This, in turn, entails most accurate manufacturing tolerances and increased manufacturing costs. In addition, it is absolutely necessary that the portion of the combination unit used as the auxiliary piston can be rotated together with the nut. On the other hand, hydraulic sealing of the auxiliary piston is necessary which must be easily rotatable in the known device. This provision is also disadvantageous with respect to manufacturing costs.
An object of the present invention is to improve a prior art disc brake with automatic adjusting device so that greater manufacturing tolerances are allowed and manufacturing costs are reduced.